This invention relates to molding products of thermoplastic or thermosetting plastic materials and particularly to products having molded therein a portion of a pre-formed elongated member or component with the remaining length and free end of the pre-formed elongated component extending from the molded product to form a projecting elongated appendage that is not imbedded or covered with the plastic material.
In forming many molded products, particularly in using an injection molding process, it is often desirable or necessary to provide a length of a pre-formed component or member, such as a tubing, wire, ribbon, rod or pin, or the like, for partial imbedding in the molded product. It is necessary to prevent the remaining length of the pre-formed component from being coated by or imbedded in the plastic material and to protect the pre-formed member projecting therefrom from being damaged during the molding process.
The prior art discloses other methods and apparatus for preventing the remaining length of the pre-formed member from being coated by or imbedded in the plastic material but does not consistently protect the preformed component from damage during the molding process or while the molded product is later removed from the mold. In injection molding, the prior art makes use of a groove or channel in one face of a female mold half to carry the remaining length and free end of the pre-formed member from the mold cavity to the exterior of the mold, or uses an aperture through a female mold half communicating with the mold cavity and the exterior of the mold.
In the former case, the use of a groove in the mold face, problems arise in the proper alignment of the preformed member, such as a flexible tubing, wire, ribbon or a rod pin, within the groove during the closing action of the mold. If the pre-formed member is not exactly aligned in the groove when the mold halves close, the high closing pressure during the molding process will damage the member and cause a reject and loss of product. In addition, extrusion of the molding material can occur along the groove around the pre-formed member and then cure around the member which will also cause a reject and loss of the product.
In the latter case, the use of an aperture through the mold body prevents the problem of "pinching" or damage to the pre-formed member during the mold closing action. However, the pre-formed member is often hard to extract from the aperture or port after the product is molded, often resulting in damage to the pre-formed member or the product upon removal, and again resulting in loss of product and wasted time in attempting to remove the molded product and it projecting elongated appendage from the mold.
When using flexible or compressable pre-formed members, such as tubing or the like, the fixed size of the aperature or port may not prevent extrusion of the molding material through the aperature around the preformed member. If this happens, then the extruded material will cure around the pre-formed member which will again cause rejection and loss of the product. In addition, extrusion of the material into the aperture or port may also make it difficult to remove the molded product from the mold. On the other hand, if the aperature or port for receiving the pre-formed member through the mold half is made smaller to reduce the extrusion problem, then it may be next to impossible to feed the pre-formed member, particularly if it is constructed of a flexible and compressible material like a flexible tubing, rope, line or the like, into and through the aperature in the mold half to begin with. In other molding processes, similar problems are presented in protecting the projecting elongated appendage from plastic coating and from damage during the molding process.
The inventor herein has previously obtained a patent, U.S. Pat. No. 4,175,554, on a prosthesis for receiving and positioning in a simulation of an erection the male penis for use by men who are sexually impotent. The prosthesis can be described generally as a penile-shaped, sleeve-like, smooth walled, elastic, relatively soft and pliable hollow cylindrical body with a closed distal end and an opposing open proximal end. A flexible, small-diameter tubing, having an outer diameter less than the wall thickness of the body has a portion thereof encased or embedded in the wall of the prosthesis, with one encased end communicating with the interior of the prosthesis at its most distal end. The tubing exits the wall of the prosthesis toward the proximal end and the remaining length and free end are used in mounting the prosthesis by the patient.
Because of all of the problems above described, the inventor found a unanimous opinion in the plastic molding industry that the prosthesis with its projecting elongated tubing could not be successfully and commercially mass-produced, using current molding technology, but it would have to be hand-made one at a time on a core by a "layering" process. The limitations and disadvantages of the prior art have been successfully overcome with the present invention, and the prosthesis, or any other plastic molded product having a projecting pre-formed member, can now successfully be mass-produced using modern injection molding or dip molding processes.